tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1 v9fs: Plan 9 Resource Sharing for Linux
2 =======================================
3
4ABOUT
5=====
6
7v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
8
9This software was originally developed by Ron Minnich <rminnich@sandia.gov>
10and Maya Gokhale. Additional development by Greg Watson
11<gwatson@lanl.gov> and most recently Eric Van Hensbergen
12<ericvh@gmail.com>, Latchesar Ionkov <lucho@ionkov.net> and Russ Cox
13<rsc@swtch.com>.
14
15The best detailed explanation of the Linux implementation and applications of
16the 9p client is available in the form of a USENIX paper:
17 http://www.usenix.org/events/usenix05/tech/freenix/hensbergen.html
18
19Other applications are described in the following papers:
20 * XCPU & Clustering
21 http://www.xcpu.org/xcpu-talk.pdf
22 * KVMFS: control file system for KVM
23 http://www.xcpu.org/kvmfs.pdf
24 * CellFS: A New ProgrammingModel for the Cell BE
25 http://www.xcpu.org/cellfs-talk.pdf
26 * PROSE I/O: Using 9p to enable Application Partitions
27 http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
28
29USAGE
30=====
31
32For remote file server:
33
34 mount -t 9p 10.10.1.2 /mnt/9
35
36For Plan 9 From User Space applications (http://swtch.com/plan9)
37
38 mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
39
40OPTIONS
41=======
42
43 trans=name select an alternative transport. Valid options are
44 currently:
45 unix - specifying a named pipe mount point
46 tcp - specifying a normal TCP/IP connection
47 fd - used passed file descriptors for connection
48 (see rfdno and wfdno)
49 virtio - connect to the next virtio channel available
50 (from lguest or KVM with trans_virtio module)
51
52 uname=name user name to attempt mount as on the remote server. The
53 server may override or ignore this value. Certain user
54 names may require authentication.
55
56 aname=name aname specifies the file tree to access when the server is
57 offering several exported file systems.
58
59 cache=mode specifies a caching policy. By default, no caches are used.
60 loose = no attempts are made at consistency,
61 intended for exclusive, read-only mounts
62
63 debug=n specifies debug level. The debug level is a bitmask.
64 0x01 = display verbose error messages
65 0x02 = developer debug (DEBUG_CURRENT)
66 0x04 = display 9p trace
67 0x08 = display VFS trace
68 0x10 = display Marshalling debug
69 0x20 = display RPC debug
70 0x40 = display transport debug
71 0x80 = display allocation debug
72
73 rfdno=n the file descriptor for reading with trans=fd
74
75 wfdno=n the file descriptor for writing with trans=fd
76
77 maxdata=n the number of bytes to use for 9p packet payload (msize)
78
79 port=n port to connect to on the remote server
80
81 noextend force legacy mode (no 9p2000.u semantics)
82
83 dfltuid attempt to mount as a particular uid
84
85 dfltgid attempt to mount with a particular gid
86
87 afid security channel - used by Plan 9 authentication protocols
88
89 nodevmap do not map special files - represent them as normal files.
90 This can be used to share devices/named pipes/sockets between
91 hosts. This functionality will be expanded in later versions.
92
93 access there are three access modes.
94 user = if a user tries to access a file on v9fs
95 filesystem for the first time, v9fs sends an
96 attach command (Tattach) for that user.
97 This is the default mode.
98 <uid> = allows only user with uid=<uid> to access
99 the files on the mounted filesystem
100 any = v9fs does single attach and performs all
101 operations as one user
102
103RESOURCES
104=========
105
106Our current recommendation is to use Inferno (http://www.vitanuova.com/inferno)
107as the 9p server. You can start a 9p server under Inferno by issuing the
108following command:
109 ; styxlisten -A tcp!*!564 export '#U*'
110
111The -A specifies an unauthenticated export. The 564 is the port # (you may
112have to choose a higher port number if running as a normal user). The '#U*'
113specifies exporting the root of the Linux name space. You may specify a
114subset of the namespace by extending the path: '#U*'/tmp would just export
115/tmp. For more information, see the Inferno manual pages covering styxlisten
116and export.
117
118A Linux version of the 9p server is now maintained under the npfs project
119on sourceforge (http://sourceforge.net/projects/npfs). The currently
120maintained version is the single-threaded version of the server (named spfs)
121available from the same CVS repository.
122
123There are user and developer mailing lists available through the v9fs project
124on sourceforge (http://sourceforge.net/projects/v9fs).
125
126News and other information is maintained on SWiK (http://swik.net/v9fs).
127
128Bug reports may be issued through the kernel.org bugzilla
129(http://bugzilla.kernel.org)
130
131For more information on the Plan 9 Operating System check out
132http://plan9.bell-labs.com/plan9
133
134For information on Plan 9 from User Space (Plan 9 applications and libraries
135ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
136
137
138STATUS
139======
140
141The 2.6 kernel support is working on PPC and x86.
142
143PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
144